A current study has demonstrated the usefulness of high-speed cinematography in obtaining detailed quantitative visualization of the complex events associated with the blinking/corneal wetting process. The camera system, operating at a rate of up to 500 pictures/sec, will be used to investigate the corneal wetting process, tear film movements, and tear fluid mixing characteristics in normal subjects and subjects with dry-eye symptoms. In addition, various types of hard and soft contact lens designs and materials will be evaluated in vivo using the high-speed system to determine their effects upon corneal wetting, tear exchange around and beneath the lenses, and the interactions with normal lid motion. Methods will include the use of electronic image intensification, fluorescent dyes, specular light techniques, and film microdensitometry. Computer processing and analysis of the data obtained will be done. The aims of the project are (1) to determine the normal and abnormal characteristis of corneal wetting, tear spreading, and drainage, with particular emphasis on dry-eye-related problems; (2) to evaluate the effectiveness of artificial tear solutions in duplicating the natural wetting actions of normal tear fluid; (3) to examine in detail the movements, tear fluid exchange, and effects upon corneal wetting of the wearing of various types of hard and soft contact lenses; (4) to examine the movements of various types of intraocular lenses due to globe rotation, with special regard to possible detrimental effects and patient intolerances; (5) to correlate wetting problems, contact lens action, lid interaction, and blinking dynamics with ocular surfacing problems and patient discomfort.